Data concerning the chemical and physical properties of the carcinogenic N-nitroso compounds will be collected. Specific emphases will include studies of: a) catalysis of N-nitrosation reactions of environmental interest by electrophilic species, including transition metal complexes; b) development and evaluation of nitrosamine degradation methods potentially applicable to laboratory problems in carcinogen decontamination and disposal; c) preparation of novel nitrosamines and their derivatives for chemical and biological studies. Possible implications of this work with respect to the overall goal of human cancer prevention will be considered.